An obligate parasite, or holoparasite, is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host.
Part of the Andes mountain range, Aconcagua is the second highest of the Seven Summits, behind only Mount Everest in Asia. At 22,837 feet (6,961 meters), not only is it the highest mountain in South America, it is the tallest peak in all of the Americas as well as the Southern and Western Hemispheres.
Mauna Kea, an inactive volcano in Hawaii, is the world's tallest mountain as measured from its base, deep in the Pacific Ocean, to its summit. The discussion over what counts as Earth's tallest mountain stems from the fact that a large amount of Hawaii's Mauna Kea is underwater, and therefore measuring it from above sea level does not do justice to its massive size.